An invention of “a method and a device for manufacturing a pneumatic tire” using a rigid core for determining the form of the inner surface of a pneumatic tire at the time of building the tire has been heretofore proposed (see, for example, Patent Document 1). Moreover, a method for removing a plurality of segments constituting a rigid core for manufacturing a tire, a method for removing and assembling the segments, and a device for implementing these methods are proposed. Here, the rigid core is used for determining the inner surface of the tire until a green tire is built or throughout the building and vulcanization of the green tire (see, for example, Patent Document 2).
In the meanwhile, the rigid core used in the former device for manufacturing a pneumatic tire has a substantially cylindrical and divided structure in which two types of a sector-shaped segment and a substantially trapezoidal mount-shaped segment, these segments being made of a metal material, are alternately disposed in the circumferential direction of the tire. At the time of manufacturing a pneumatic tire, the multiple sector-shaped segments and mount-shaped segments are alternately disposed in the circumferential direction of the tire to form a cylindrical shape, thereby constituting a rigid core. After the tire is vulcanized and thus molded, the multiple sector-shaped segments are pulled in a radial direction, and separated from the mount-shaped segments.
Nevertheless, in order to separate and assemble the rigid core thus divided in plurality, a lot of work and time are needed. Moreover, a sophisticated skill is required for the separation and assemblage of the rigid core serving as an inner mold without causing any damage. Thus, there has been a problem of a significantly poor operating efficiency.
In the latter method and device for removing the segments constituting the core for manufacturing a tire, when the multiple segments having been divided into the different types are removed from the inside of the tire, the different types of the segments are removed one by one. Accordingly, a lot of work and time are needed to remove all the segments from the inside of the tire. Moreover, at the time of the removal, the segment is pulled out while the upper and lower edge portions of the segment are being clamped by a clamp mechanism. As a result, there has been a problem that the method and device have an adverse influence on the quality of a tire thus built and on the accuracy of building a tire.    [Patent Document 1] Japanese patent application Kokai publication No. 2003-523851    [Patent Document 2] Japanese patent application Kokai publication No. 2002-307440